Some medical X-ray imaging techniques can detect variations in contrast of regions of interest in a subject, including different organs, tissues, cells and the like. To increase the contrast of regions of interest, some of the imaging techniques utilize the administration of one or more contrast-enhancing agents to a subject. The contrast-enhancing agents can accentuate existing differences in contrast between different areas of interest, or can produce differences in contrast where such differences do not exist without use of the agents.
There have been advancements in medical X-ray imaging, specifically relating to the instruments or machines used to detect the differences in contrast. These advancements include increases in the speed of the instruments, increases in the resolution of the instruments, and the like. These advancements have provided, in part, for new medical imaging methods. One example method, whole-body imaging, can yield information on the vasculature of the entire body of a subject.
Compared to advances in the instruments used for X-ray imaging, advances in contrast-enhancing agents have not been as forthcoming. Current contrast-enhancing agents for medical imaging using X-rays can have limitations for applications such as whole-body imaging due to, among other things, rapid clearance from the body of a subject, greater than desired extravasation, renal toxicity and inability to target specific areas of the body of a subject.